A couple of years ago I was talking to a friend in Russia who owns a factory that produces very high-end commercial radio equipment (for example, microwave relay stations that very high-end traders use to reduce lag). High cost, high technology, lots of IP. (By the way, the only example I could find, really, of Russia producing something this advanced technologically). I am not in contact with the guy right now, but I am pretty sure he will have to close manufacturing because he obviously needs parts from abroad.
But the point is - he talked to me about dealing with China or selling in China. And he said, basically, he completely gave up on it. He said that every negotiation was: "we will buy from you, this once or twice, but you will give us the technology, so we can copy it and not buy from you again.". He said it was completely blatant and open, they were not hiding it.
That is why he refused to sell in China. Apparently some people don't value their stuff enough to do the same thing.
A lot of companies don't because if you can open up your markets and sell 20% more product, even if only for a few years before they copy it...doesn't matter. The incentive structures are setup so that those in control only consider the short-term benefit.